A former Welsh disco dancing champion suffering from a chronic fatigue illness is calling on the UK government to invest more in research.

Beth Llewellyn, aged 20, from Milford Haven will travel to Downing Street on Monday with five other young sufferers to deliver a petition directly to Prime Minister Tony Blair.

She is one of more than 240,000 people across Britain living with myalgic encephalomyelitis - known as ME.

She and her family say not enough is being done to support sufferers, and they are hoping that the trip to London will help draw attention to the problem.

Until two years ago Beth held hopes of becoming a professional dancer. She was studying drama and technical theatre at Pembrokeshire College and was the six-times winner of the Welsh Disco Dancing Championship.

Now she spends her days sitting on her bed, watching television and surfing the internet.

Pain in her joints and muscle spasms mean she can no longer walk, and her mother has had to become her full-time carer.

Beth's mother is her full-time carer

Beth contracted ME after getting a viral infection. She says doctors know very little about the illness and do not know how to help her.

"It's very frustrating," she said. "I have my good days and bad days, and when I have my good days I want to do so much but I can't.

"You just wish someone out there would say, 'I can help you'. Each day you're hoping someone will. But at the moment there isn't anyone who can help, and it is very, very hard."

It has been estimated that chronic fatigue syndrome costs the British economy billions of pounds.

Research carried out for the charity Action for ME has suggested the total cost is £3.5bn a year - around £15,000 for each person with the syndrome.

The figure is based on the cost of medical treatment, loss of earnings and the cost of state benefits.

The Department of Health acknowledged ME is a medical illness only last year. It followed years of campaigning by patient groups.